I have the option to shower at the office, so I don't need to worry about that.

Though, I need to bring my repair gear including an inner tube, a multi-tool and some tire levers and a tire repair kit (you never know). Next to that I eat one banana, a few cookies and 2 sandwiches at work which makes me pretty sure I don't have enough space in my back pockets. Need to bring 2 cellphones as well, a pair of glasses, a wallet with id and such, keys (and on late shifts or Saturdays I bring a harddisk with my favorite tv series along with me as well as I get bored by being alone in the office without any sounds or movement around me).

The lock will from now on stay at the office, which was quite an obvious step actually.

During days like these it's hard not to take a backpack with me. In the morning it's too cold to wear shorts, and in the afternoon it's too warm to wear long pants. Same goes for the jacket I wear in the morning.

As you said, planning can be a pain, but I might as well give it a try.